A five-year project is proposed involving collaboration between the University of California, Berkeley and the California 4-H Youth Program, administered by UC and open to all youth 9-19 years of age. The primary objective is to develop and evaluate two educational interventions for preventing and reducing the use of smokeless tobacco among youth. Other objectives are to identify patterns and determinants of young people's smokeless tobacco (ST) use; to develop an empirically-based model of ST use; to develop assessment procedures to determine long-term program effectiveness; and to test the effectiveness of using the California 4-H program as an intervention vehicle. The study population will be members of 4-H clubs throughout California. The project involves 3 interlocking phases: (1) exploratory research leading to a formal survey of approximately 2800 youth, and then to the development of an empirically-based model of ST uptake and use; (2) the development of 3 educational curricula (ST, integrated tobacco including ST and cigarettes, and control. Two "booster" sessions per curricula, intended for later delivery, will also be developed. Instruction will take advantage of natural multi-age groupings. County-based 4-H academic personnel will participate in program development and data collection. After training, volunteer adults who normally lead 4-H clubs will teach the educational sessions. Effectiveness of curricula will be tested in a 3 (curricula) x 2 (presence of boosters) factorial design. Outcome measures will include self-reports of ST and cigarette use supplemented by saliva cotinine analysis, and by demographic, social, and psychological mediating variables. Analysis will use variable means of 180 4-H clubs (30 per cell), providing a true experiment at the club mean level. Individual level data analysis (from approximately 6200 subjects), will identify risk factors and determine the influence of entry variables; (3) Phase 3 will involve long-term followup through 27 months and 5 measurement points after immediate posttest. Individuals leaving 4-H will be carefully tracked for followup. Local adoption of ST-related projects by 4-H clubs will be monitored. Program cost-effectiveness will be analyzed and is expected to be excellent due to volunteer adult leadership of sessions. Important audiences for dissemination of project materials include State 4-H programs across the country, other out-of-school educational programs, and schools.